Lint burner for a domestic dryer



May 5, 1964 B. L. BRUCKEN LINT BURNER FOR A DOMESTIC DRYER 3 Sheets-Sheet 1 Filed Jan. 23, 1958 INVENTOR. Byron Z Bracken 644" ms ATTORNEY y 1964 B. L. BRUCKEN LINT BURNER FOR A DOMESTIC DRYER Filed Jan. 23, 1958 5 Sheets-Sheet 2 vlfllllllllllvllllffllffl IIIIIIIIIIIIIIIIJ'.

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10, 5 H fir INVENTOR. 012; Z Brad e2 BY H15 AITORNE May 5, 19 B. L. BRUCKEN LINT BURNER FOR A DOMESTIC DRYER 3 Sheets-Sheet 3 Filed Jafi. 23, 1958 INVENTOR. 531m)! 1. Brae/ w BY W 25% HIS ATTORNEY i United States Patent ffice 3,132,666 LINT BURNER FGR A DOMESTIC DRYER Byron L. Bracken, Dayton, Ohio, assignor to General Motors Corporation, Detroit, Mich, a corporation of Delaware Filed Jan. 23, 1958, Ser. No. 710,808 16 (Ilain'is. on. 34:79

This invention relates to a domestic appliance and more particularly to a clothes dryer having improved means for collecting and destroying lint evolved during the clothes drying process.

A serious objection to the use of domestic clothes dryers is the evolution of lint during the drying process. This lint is either entrapped on a screen disposed in the path of the air flow through the dryer or is merely exhausted from the dryer where it becomes an unsightly appendage to any surface in the laundry area. The collecting screen has the disadvantage of requiring frequent cleanings in order to prevent an undesirable build-up of lint on the surface thereof. This not only reduces the dryer efliciency but creates a fire hazard as well as temperatures increase in response to the clogged screen restriction disposed in the pathof the dryer air flow. Copending applications S.N. 635,635, now Patent No. 3,081,554, filed January 23, 1 957, and S.N. 698,193, now Patent No.

3,001,295, filed November 22, 1957, have proposed ways in which lintburning may be done at a selected point in the drying cycle. The latter of these applications teaches also the desirability of a delay between the energization of the smoke and odor filter heater and the energization of the lint burn heater. It is now proposed to obviate the necessity for selectively energizingthe lint burn circuit by using a continuous lint burning process whenever the dryer is in operation. l I g Accordingly, it is an object of this invention to provide a continuous lint burning arrangement for a clothes dryer'wherein the products of combustion are .continuously;changed; to substantially colorless" and odorless products by a suitable-filter element.

It is a more specific object that a cylindricallint collecting screen be rotated in the air flow path and adapted to sequentially collect lint at one point in-the rotation and burn the lint at another point.

It is a further object of this invention to provide a bypass burn and filter chamber adjacent-a portion ofthe cylindrical lint collecting screen whichiis adapted to withdraw continuously the products of combustion therethrough.

Further objects and advantages of the present invention'will be apparent from the following description, ref+ erence being bad to the accompanying drawings, wherein a preferred form of the present invention is clearly shown j Inthedrawings: g FIGURE 1 "is a front elevational view, with parts broken away, of a clothes dryer incorporating the features ofthis invention; u a j V FIGURE 2 is a side elevational'view taken along line 22ofFIGURE-1; g f

FIGURE 3 is a partial top sectional view of the lint collecting arrangement taken substantiallyalong line 33 ofFIGURE 1; and i F IGURE' 4'is a front elevational view, with parts broken away, ofthe lint collecting'and burning arrangement taken along line 4-4 of. FIGURE 3; I

With reference now to FIG. 2, this invention is comprisedof 'a cabinet Ill-having a top wall 11, a front wall 12, a rear wall 14 and a base 16. The front wall 12 of the cabinet is formed-with an opening 18 to receive 9 a hingedly mounted access door 20. Enclosed within 'the cabinetltl isa tumbling drum or casing 22 having a rear wall 24, a front wall 26 and an imperforate peripheral portion 28having raised batfles 30. The drum 22 is carried on an affixed shaft 32 which is journaled in a bearing 34 secured to a cabinet bulkhead 36 extending from the top 11 of the cabinet to the base 16 and parallel to the rear wall 14. Formed on the front wall 26 of the drum is a neck portion 38 which extends outwardly into underlying relationship with an inwardly extending flange portion 40 of the cabinet opening 18. Mounted within a spacer 42 disposed within the cabinet opening 18' is a front air flow baflle, shown generally at 44. A neck portion 46 of the air flow baflie 44 projects inwardly into underlying relationship with neck portion 38 of the tumbling drum. Spacer 42 so locates an annular flange 50 of the air flow baflle 44 in relation to the" access door 20 that a passageway 52 is formed to permit end wall 68. This chamber 58 provides the sole receptacle into which air proceeding from the tumbling drum 22 by Way of front duct 56 flows. The top wall 66 is formed with an opening 70 which cooperates with the open end of the front duct 56, the duct 56 having a flange 72 which overlies the edge of opening 70 for attachment thereto. An opening 74 in the front wall 62 of the chamber is covered by a plate 76. The plate 76 in conjunction with a removable access door 78 in the front wall 12 of the dryer cabinet permits access to the interior of the lint collecting chamber 58. The rear wall 60 of the chamber is formed with a flanged opening 80 through which air is chamber 58. p

With reference again to FIG. 2, the clothes' tumbling drum 22 is rotated through a pulley system, shown generally at 82, by a prime mover'or motor 84. Directly exhausted from the lint collecting connected to the motor84 is a blower 86 adapted to exhaust air from the dryer by way of a blower exhaust outlet 88. The blower housing is formed with an extended inlet collar portion 90 which projects toward the outlet opening 80 of the lint collecting chamber 58. A conduit 92, either. flexible or rigid, extends between the flanged openings 80 and 90 and connects the blower 86 in air flow, relationship to the lint collecting chamber 58.

Normal air flow through the tumbling drum 22 is thus effected by way of an air inlet opening 94 through air-tight annular chamber 166 between the bulkhead 36 and the rear wall 24 of the tumbling drum,- an annular seal 108 of felt or any other suitable material, is installed. The seal .108 is so placed to form the outer periphery of the annular chamber 106 and supported in this position on an annular bracket 110 fastened to the bulkhead 36.

From the annular chamber 106 air flowsto the interior of the tumbling drum 22 through apertures 112 in the rear Wall 24 of the tumbling drum. Thus, it may be seen that normal airflow-through the dryer proceeds on a course defined by cabinet inlet opening 94 into the heater housing 96 where it is warmed by the primaryheater 104.

Patented May 5,1964

tumbling drum downwardly through the front duct 56 and into the lint collecting chamber 58.

The novel continuous lint collecting and burning arrangement will now be more fully described. With referenceto FIGS. 3 and 4, a lint collecting drum, shown generally at 114, is disposed transversely in the path of air flow proceeding from the lint collecting chamber58 to the conduit 92. The periphery of the drum 114 is formed of screen or wire mesh 116 which is wrapped around the outside of an inwardly extending flange 117 of an imperfo rate circular dished-out support member 118. The screen mesh should be of such size that it sufficiently entraps lint from the air without unduly restricting air fiow. A 30'- mesh screen has been found, satisfactory for this purpose. The screen support member 118 carries a shaft 122 i which is journalled at 128 in front wall 62 of the lint collecting chamber; The shaft 122 has its one end secured to the screen support member 118 and mounts at its other end a drive pulley 124; The inner end of the peripheral screen 116 is supported and formed into a cylindrical shape on a collar 126. Thus, it is seen that the screen drum or cylinder is formed solely by the support action of the outer circular imperforate member 118 and the inner collar 126. The screen drum 114 is supported in correct relation to the lint collecting chamber 58 by the shaft 122 which isjouralled in the wall 62 of the chamber 58. A system of air bafiles and seals is utilized at the inner end of the screen drum to assure correct filtration of and lint elimination from the air flow. A measure of support is supplied by the cooperation of the screen support collar 126 and the bafile and seal system. To more fully understand this relationship, the system will be clearly set forth next following.

To secure efficient operation of the rotating drum, it is desirable that air flow through the drum screen 116 be restricted to that portionof the screen which happens to be moving along the path marked A in FIG. 4. The remainder of the screen drum periphery is moved through a comparatively draft-free section 135 of the lint collecting chamber 58. In this manner, lint is entrapped on that portion of the screen 116 that is moving through the area marked A. As the screen continues to rotate, the lint is carried into the draft-free section 135 in which the lint burning and smoke eliminating equipment later described, is housed. Construction necessary to accomplish the desired air flow is as, follows. The imperforate support member 118 prevents air from flowing into the axially outer end of the drum 114. Any suitable bafile (not shown) is disposed between the surface 118 and wall 62 to lessen air flow around the outer end of the drum. To

minimize air flow around the axially inner end of the drum, a semi-annular seal 128 is alfixed to the rear wall 60 of the chamber 58. The seal 128 is formed with a groove or depression 127 which is adapted-to slidably receive a portion 129 of the collar 126 extending beyond the edge of the screen 116. A spring 131 is provided between the journal bearing 120 and the screen support member 118. Thisspring urges the extended collar portion 129 at the opposite end of the drum into the groove 127, thus effectively minimizing air flow around the inner end of the drum.

As aforesaid, it is desirable to keep a section 135 of the lint collecting chamber comparatively draft-free. For this purpose, an imperforate baflle 130 is affixed to the chamber wall 60 by a number of tabs 132 and extends within the drum 114 to a terminus closely adjacent, the support plate 118. The baflie also lies closely adjacent that portionof the screen 116 which is passing through the draft-free area 135 and substantially prevents air which has passed through the screen along path A from entering the area 135. On the outside of the rotating drum 114, the area 135 is protected from air flow currents by a baflie 134 affixed to the bottom wall 64 of the chamber 58. This baflle 134 extends along the entire length of the drum 114 and substantially restricts air flow to that portion of the screen 116 passing along the path A. A similar bafile 136 is affixed to chamber top wall 66 and serves a similar air flow restricting function, at that location.

As best seen in FIGS. 3 and 4, a lint burning and smoke eliminating housing 138 is fastened in air-tight relationship to the top wall 66 of the air collecting chamber 58, as by flanges 140. The housing 138 has a portion 139 which extends into the draft-free area 135, said portion having an opening 142 closely adjacent a section of the screen116 which is rotating through the draft-free area 135. An exhaust opening 144 leads from the housing 138 by way of a conduit 146 to an inlet'148 in the blower inlet collar 90 (FIG. 2). The housing 138 is divided into a lint burning section 141, a filter or catalyst receptacle 143 and a filtered air receiving chamber 145. The catalyst receptacle 143 is formed by a top wall 150 and a bottom wall 152 which extend the length of the housing 138. The filtering agent 154 of aluminum oxide material impregnated with a platinum base deposit or other suitable smoke and odor eliminator, is reposed therein. The walls 150 and 152 are ported as at 156 to permit air flow therethrough and across the filtering agent 154 therein. A lint burning heater 158 is placed in the lint burning section 141 between the screen element 116 and the filtering agent 154.

To rotate the screen cylinder or drum 114, the pulley 124 is driven by a belt 160 and a shaft 162 supported at 164 to the dryer cabinet base (FIG. 2). The prime mover 84 is adapted by way of a pulley system 166 to drive the shaft 162 and thus rotate the lint collecting screen cylinder or drum 114. The rotation of the cylinder 114 should be slow to permit complete incineration of the lint which the rotating screen carries beneath the lint burning section 141. For this reason a speed reducing means 168 is interposed between the prime mover 84 and the screen cylinder 114 to' reducethe rotational speed of the cylinder to the desired r.p.m. A rotational speed of A to /2 r.p.m. has been found satisfactory.

The operation of the continuous lint burning arrangement will now be morefully understood with reference to a complete description of a normal drying cycle. Moist clothes are introduced to the tumbling drum 22 of the dryer by way of access door 20. Any conventional timing mechanismis set .to provide a selected drying cycle. The motor 84 is thus energized to cause the blower 86' to draw into the tumbling drum and exhaust it from the cabinet 10 by way of an exhaust conduit (not shown) of any conventional type. To Warm the air before it enters the drum 22 a heater 104 is disposed in the path of air entering the cabinet at opening 94. Air in passing through the drum 22 picks up moisture from the damp clothes as well as lint evolved during the agitation process. This lint and moisture filled air proceeds from the drum 22 by way of opening 38 and passageway 52 into the front duct 56 and subsequently into the lint collecting chamber 58.

Since the lint collecting and burning process continues throughout the dryer and blower operation, it is seen that the lint collecting screen cylinder or drum 114 is rotated whenever the prime mover 84 is energized. Therefore, it is also apparent that cylinder 114 is caused to rotate any time thatthe blower 86 is operating. This results in air following a path from the front duct 56 to the lint collecting chamber 58, through the portion of the rotating screen 116 which is moving'along the path A and into the duct 92 on its way to the blower inlet 90. In passing through'the transversely disposed rotating lint collecting screen 116, the lint is entrapped thereon, Since the screen 116 rotates continuously in the direction shown on FIG.

the opening 142 in the lint burning section 141. The lint burning heaters 158 are energized simultaneously with the blower and thus ignite and char any lint passing thereby. .It is also apparent that with the heater 158 energized continuously, the catalyst or filtering agent 154 remains activated to eliminate any smoke and odor fromthe products of combustion passing thereover as the lint isburned.

Of course, it should be recognized that the smoke and odor eliminating means of this invention is effective only if an air flow exists from the opening 142 in the lint burning chamber to the conduit 146. It is for this reason that conduit 146 is connected immediately adjacent the blower inlet 90. It has been found that the pressure drop occurring through the conduit 92 provides the necessary resistance tonormal dryer air flow to effect a small air circulation from the lint burning section 141 to the blower by way of conduit 146. However, it is within the purview of this invention to equip the conduit 92 with a baflle 170 having an orifice 172 to increase the pressure differential between the blower and the lint collecting chamber outlet 80. In this manner air flow through the lint burning housing 138, past thefiltering agent 154 and through the conduit 1'46 failitated. Y j

While the form of embodiment of the invention as herein disclosed constitutes a preferred form,it is to be understood that other forms might be adopted, as may come within the scope of the claims which follow..

What is claimed is as follows:

1. In combination a clothes dryer including an outer cabinet, a tumbling drum having a peripheral wall rotatable in said outer cabinet, said tumbling drum having a rear perforated wall and a front access opening; an air discharge duct communicating with said opening; means for heating air for said tumbling drum; a blower for circulating heated air through said drum and said duct and having a blower inlet; a lint collector rotatably mounted in said duct; a lint burning and smoke eliminating cham her having an inlet extending through a wall of said duct to a position adjacent a portion of said collector and an outlet; means connecting said outlet to said blower inlet; altering means in said chamber in series flow relationship to said chamber inlet for eliminating said smoke; a heater adjacent said altering means for burning said lint and activating said altering means, and power means for rotating said collector.

2. The combination of claim 1 wherein said lint collector is comprised of a cylinder disposed in said duct transverse to the flow of air from said drum; said cylinder having a perforated peripheral wall, a closed end adapted to be driven by said power means and an open end in communication with said blower.

3. A continuous lint burning fabric agitator comprising a casing for agitating said fabric; a blower for producing one air flow through said casing; duct means connecting said casing and said blower; a lint collecting surface rotatably mounted in said connecting duct means; housing means adjacent said surface and communicating with said connecting duct means; a lint burn heater in said housing means adjacent said surface; a smoke and odor altering means adjacent said heater; means for withdrawing another air flow through said housing means; and power means for moving said lint collecting surface.

4. A continuous lint burning fabric agitator comprising a casing for agitating said fabric; a blower for producing one air flow through said casing; duct means connecting said casing and said blower; a lint collecting surface movably mounted in said connecting duct means; housing means adjacent said surface and communicating with said connecting duct means; a lint burn heating means in said housing adjacentsaid surface; a smoke and odor altering means adjacent said heating means; second duct means 6 for conveying another air flow through said housing means; and power means for moving said lint collecting surface.

5. In combination a clothes dryer including an outer cabinet, a tumbling drum having an imperforate peripheral wall rotatable in said outer cabinet, said tumbling drum having a rear perforated wall and a front access opening; an air discharge duct communicating with said opening; means for heating air for said tumbling drum; a

.blower for circulating heated air through said drum and said duct and having a blower inlet; a lint collector rotatably mounted in said duct; a lint burning and smoke eliminating chamber having an inlet extending through a wall of said duct to a position adjacent a portion of said collector and an outlet; aconduit connecting said outlet to said blower inlet; a catalyst element in said chamber in series flow relationship to said chamber inlet for eliminating said smoke; a heater in heat transfer relationship to said portion and said element for burning said lint and activating said catalyst element, and power means for continuously rotating said collector and driving said drum and said blower.

6. A continuous lint burning fabric agitator comprising a drum for agitating said fabric; a blower for producing a first air flow through said drum; a duct connecting said drum and said blower; a rotatably mounted lint collecting surface in said duct between'said blower and said'drum; a compartment adjacent said surface and communicating with said duct; a lint burn heater in said compartment adjacent said surface; a smoke and odor altering means adjacent said heater; second duct means for conveying a second air flow through said compartment; and power means for moving said drum, blower and lint collecting surface.

7. In combination a clothes dryer including an outer cabinet, a tumbling drum having a peripheral wall rotatable in said outer cabinet, said tumbling drum having a rear perforated wall and a front access opening; an air duct communicating with said opening; means for heating air for said tumbling drum; a blower for circulating heated air through said drum and having a blower inlet; a lint'collector rotatably mounted in said duct; a lint burning and smoke eliminating chamber having an inlet extending through a wall of said duct to a position adjacent a portion of said collector and an outlet; means connecting said outlet to said blower inlet; an air flow restrictive device in said duct to increase air flow through said chamber; a smoke altering means in said chamber in series flow relationship to said chamber inlet for eliminating said smoke; a heater adjacent said portion and said smoke altering means for burning said lint and activating said smoke altering means, and power means for rotating said collector.

8. A fabric dryer comprising a casing defining a drying chamber and having an air inlet opening and an air outlet opening therein, means for consuming lint carried from the fabric through said air outlet opening, and means for circulating air sequentially through said drying chamber and the lint consuming means, said lint consuming means including duct means connected to said air outlet opening and having a first cross sectional area, a screen member positioned extending across said duct means transverse to the flow of air from said air outlet opening to form a'lint catching barrier and having a second substantially greater area, said screen member being movably mounted and positioned so that movement of said screen member causes at least a portion thereof to alternately intercept and then be removed from said duct means, means for moving said screen member, and heating means positioned outside said duct means adjacent that portion of said screen member which is removed from said duct means for burning lint caught. on said portion of said screen member.

9. A clothes dryer comprising a clothes container; means for providing a draft of warm air through said container; .exhaust duct means for the air connecting said container to atmosphere; and means for consuming lint carried from the clothes into said exhaust duct means; said last mentioned means comprising a duct having a first cross sectional area, a screen'member having a second substantially greater area positioned extending across, said duct to form a lint catching barrier thereacross, said screen member being movably mounted and positioned so that movement of said screen member causes at least a part thereof to alternately intercept and then be removed from said duct, means for moving said screen member, and a low energy heat source positioned outside said duct adjacent that part of said screen member which is also outside said duct for burning lint caught on said part of said screen member.

10. The apparatus defined in claim 9 wherein said heat source is an electrical resistance device.

11. The apparatus defined in claim 9 wherein a smoke eliminating catalyst is provided downstream of the point at which lint is burned.

12. The apparatus defined in claim 11, wherein said catalyst is a noble metal selected from the group consisting of platinum, palladium, and mixtures thereof.

13. A clothes dryer comprising a clothes container; means for providing a draft of warm air through said container; exhaust duct means for the air connecting said container to atmosphere; and means for. consuming lint carried from the clothes into said exhaust duct means; said last mentioned means comprising a duct having a first cross sectional area, a screen member'having a second substantially greater area positioned extending across said duct to form a lint catching barrier thereacross, said screen member being rotatably mounted and positioned so that rotation of said screen member causes at least a part thereof to alternately intercept and then be removed from said duct means for rotating said screen member, and a low energy heat source positioned outside said duct adjacent that part of said screen member which is also 7. means and exhaust duct means each connecting said container to atmosphere; means for creating a draft of air from said inlet ductmeans through said container to said exhaust duct means; means for heatingair prior to its passage into said container; and means for consuming lint carried-from the clothes into said exhaust duct means; said last mentioned means comprising a duct having a first cross sectional area, a screen member having a second substantially greater area positioned extending across said duct to form a lint catching barrier thereacross, said screen member being rotatably mounted and positioned so that. rotation of said screen member causes at least a part thereof to alternately intercept and then be removed from said duct, means for rotating said screen member, and a low energy heat source positioned outside said duct H adjacent that part of said screen member which is also outside said duct for burning lint caught on said part of said screen member.

15. The apparatus defined in claim 14 wherein said draft creating means is positioned in said exhaust duct means downstream of said means for consuming lint.

16. The apparatus defined in claim 14 wherein common drive means are provided in rotative relation both to said container and to said screen member.

References Cited in the file of this patent UNITED STATES PATENTS 839,797 Wood L Dec. 25, 1906 1,189,777 Bartholomew July 4, 1916 2,809,025 Pettyjohn Oct. 8, 1957 FOREIGN PATENTS 620,906 Great Britain Mar. 31, 1949 

8. A FABRIC DRYER COMPRISING A CASING DEFINING A DRYING CHAMBER AND HAVING AN AIR INLET OPENINGS AND AN AIR OUTLET OPENING THEREIN, MEANS FOR CONSUMING LING CARRIED FROM THE FABRIC THROUGH SAID AIR OUTLET OPENING, AND MEANS FOR CIRCULATING AIR SEQUENTIALLY THROUGH SAID DRYING CHAMBER AND THE LINT CONSUMING MEANS, SAID LINT CONSUMING MEANS INCLUDING DUCT MEANS CONNECTED TO SAID AIR OUTLET OPENING AND HAVING A FIRST CROSS SECTIONAL AREA, A SCREEN MEMBER POSITIONED EXTENDING ACROSS SAID DUCT MEANS TRANSVERSE TO THE FLOW OF AIR FROM SAID AIR OUTLET OPENING TO FORM A LINT CATCHING BARRIER AND HAVING A SECOND SUBSTANTIALLY GREATER AREA, SAID SCREEN MEMBER BEING MOVABLY MOUNTED AND POSITIONED SO THAT MOVEMENT OF SAID SCREEN MEMBER CAUSES AT LEAST A PORTION THEREOF TO ALTERNATELY INTERCEPT AND THEN BE REMOVED FROM SAID DUCT MEANS, MEANS FOR MOVING SAID SCREEN MEMBER, AND HEATING MEANS POSITIONED OUTSIDE SAID DUCT MEANS ADJACENT THAT PORTION OF SAID SCREEN MEMBER WHICH IS REMOVED FROM SAID DUCT MEANS FOR BURNING LINT CAUGHT ON SAID PORTION OF SAID SCREEN MEMBER. 